The present invention is directed to a quick turn around time system and method of use for improving wafer processing within an automated wafer fabrication FAB.
In a wafer fabrication facility, preferably a 300 mm FAB, production equipment operates using a first in, first out (FIFO) sequencing rule for processing work orders of wafer lots. High priority work orders or super hot lots are also processed in sequence according to the FIFO rule. Existing automated FABs that use the FIFO sequencing rule do not provide an adequate means for sequencing high priority orders or super hot lots for processing before lower priority work orders once work orders have been tracked into a piece of fabrication. Therefore, high priority or super hot lots will be queued in internal equipment buffers and must wait a long time in equipment before being processed.
Typically, in a semiconductor wafer process, an operator conventionally performs an operation of forming works such as wafers into a batch. In particular, from within a plurality of works transported to a batch processing piece of fabrication equipment, those of the works for which processing conditions are the same are selected by the operator, and a predetermined number of such works are put in order and formed into a batch and then supplied to the batch processing piece of fabrication equipment by the operator.
Further, the operator has a heavy responsibility in that the operator must form works into a batch after a preferential order of the works is recognized. The presence of the operator presents an undesirable labor intensive impediment. In addition, as the size of wafers to be handled increases, the number of works which can be prepared for a production line decreases, and as a result, the batch process piece of fabrication equipment fails in formation of a batch from a predetermined number of works.
Batches of wafer lots are formed during batch processing and are inserted into a batch processing piece of fabrication equipment""s internal queue. However, once inserted into the batch processing equipment""s internal queue, the formed batch cannot be modified. A batch is formed only from the works currently prepared for the batch process piece of fabrication equipment, even if works having a higher preferential degree or degrees than the works prepared in the batch are prepared for the batch process apparatus before the prepared works are actually processed by the batch process piece of fabrication equipment. When the number of works equal to the predetermined formation number is already prepared for the batch process piece of fabrication equipment, the works of the higher preferential degree are left without being supplied until the next timing for formation of a batch. Formed batched are not processed preferentially but are processed after processing of other works.
Thus, if a super hot lot needs immediate processing, the super hot lot batch must wait for the formed batch to be processed before the super hot lot batch may be tracked into a piece of batch fabrication equipment. As a result, failure in delivery of products on or prior to the delivery date can occur. It is desirable to provide an adjustable internal buffering queue disposed a piece of fabrication equipment that cooperates with a real time dispatching system to prioritize wafer lot orders disposed within a piece of fabrication equipment.
It is desirable to optimize dispatching rules within an adjustable internal buffering queue disposed within a piece of fabrication equipment.
It is desirable to ensure high priority or super hot lots can be processed before lower priority lots.
It is desirable to create a dispatching mechanism to speed up production lots having a high priority turn ratio in a piece of fabrication equipment having an internal buffer.
The present invention provides equipment automation for wafer fabrication facility, preferably a 300 mm FAB, for optimally processing super hot lots within a piece of fabrication equipment having an internal buffer. The present invention provides internal buffer optimization for both in-line processing pieces of fabrication equipment and batch processing pieces of fabrication equipment. The present invention further provides a load port reservation for optimally tracking in a work order into a piece of fabrication equipment.
The piece of fabrication equipment""s software is integrated with a host real time dispatching (RTD) system to establish processing capacity adjusted according to processing order for production equipment. To make processing equipment more efficient, dispatching rules are optimized for lots entered into an internal buffer in accordance with a software rule database. The rule database further provides for inserting super hot lots into a pre-WIP list disposed within the real time dispatching system. Thus, super hot lot or high priority lots will be processed in a lot by lot manner.
The present invention provides delay timing for editable batch formation, allowing for batches waiting to be processed within a piece of fabrication equipment to be edited by adding, removing, or exchanging a batch.
More particularly, the present invention provides a quick turn around time (QTAT) system for locating an optimal arrangement of work orders within a wafer fabrication facility providing:
a real time dispatching system having a software rule database; and
at least one piece of fabrication equipment having an internal buffer in communication with the software rule database, wherein the real time dispatching system and the at least one piece of fabrication equipment cooperate to optimally prioritize a work order disposed within the internal buffer of the at least one piece of fabrication equipment in accordance with instructions specified by the real time dispatching system software rule database.
The quick turn around time system further has:
an equipment operator interface in operative communication with the at least one piece of fabrication equipment, wherein the equipment operator interface is in further operative communication with the real time dispatching system for prioritizing at least one work order disposed within the internal buffer of the at least one piece of fabrication equipment, wherein the real time dispatching system rule database cooperates with the equipment operator interface to insert at least one super hot lot work order into a real time dispatch system pre-work in progress list in accordance with the rule database.
Additionally, the present invention provides a method of using the QTAT, the method of use having the steps of:
providing a real time dispatching system having software rule database;
providing at least one piece of fabrication equipment having an internal buffer in communication with the software rule database; and
prioritizing a work order disposed within the internal buffer of the at least one piece of fabrication equipment in accordance with instructions specified by the real time dispatching system software rule database.
Additionally, the method further has the step of:
providing an equipment operator interface in operative communication with the at least one piece of fabrication equipment, wherein the equipment operator interface is in further operative communication with the real time dispatching for prioritizing at least one work order disposed within the internal buffer of the at least one piece of fabrication equipment.
The method further has the steps of:
tracking in a work order into a piece of fabrication equipment using the real time dispatching system;
selecting a process to be performed on a work order;
processing the optimally prioritized work order disposed within the internal buffer of the piece of fabrication equipment; and
tracking out the completed processed work order from the piece of fabrication equipment.
The step of tracking in a work order into a piece of fabrication equipment further has the step of using a load port reservation system in communication with the real time dispatching system for optimally tracking work orders into a piece of in-line processing equipment, wherein the step of using the load port reservation system for optimally tracking a work order into a piece of in-line processing equipment further has the steps:
identifying at least two pieces of fabrication equipment capable of performing a same specified recipe for processing a work order, the at least two pieces of fabrication equipment each having an associated load port;
checking the availability status of each associated load port; and
sending an available work order to a first available one of the associated load ports for processing by the associated piece of fabrication equipment having the first available load port.
Additionally, the step of tracking in a work order into a piece of fabrication equipment further may optionally provide the step of:
using a plurality of batch edit functions for optimally tracking work orders into a piece of batch processing equipment using the equipment operator interface to select a batch edit function, wherein the batch edit function is selected from the group of add, remove, and exchange.
An alternative method of using the QTAT is provided herein, wherein the alternative method of using a quick turn around time system to optimize dispatching of work orders within a wafer fabrication facility has the steps of:
providing a real time dispatcher having a work in progress list, and a pre-work in progress list for managing work orders;
providing a user interface in operative communication with the real time dispatching;
using the real time dispatcher rule database to optimize an internal buffer disposed within a piece of fabrication equipment;
using the real time dispatcher rule database to a provide a load port reservation system;
using the real time dispatcher rule database to delay timing for forming a batch for batch processing; and
using the real time dispatcher rule database to insert a super hot lot work order into the pre-work in progress list.